Let me just say that I believe Colossians 2:16-17 is making the point that we (the Church which is His body) are not commanded to be keeping these things.
However, the passage itself DOES say, "... which ARE [present tense, plural] A SHADOW [singular] of the things [plural] COMING [present participle]"
(IOW, I am pretty convinced that in the trib years [FOLLOWING our Rapture/THE Departure], that these things will aid Israel in their coming to faith in Christ ["making the connections," so to speak], one of the purposes of the trib years is to bring Israel into the new covenant, as I see it; this is who Matt24:9b is talking about [early-ish in the trib] where it says, "and ye shall be hated of all nations for My name's sake" and v.14's "And this gospel of the kingdom SHALL BE PREACHED in all the world for a witness unto all the nations..." [mid-point and second half] that is, DURING the trib yrs [the Church which is His body will have already been "raptured" out, and which "event" will itself be a primary "impetus" pointing Israel to Christ!])